Decolorization Of Disperse Red 3B By Consortium Of The Chlorella Sorokiniana XJK And The Fungus Aspergillus Sp. XJ-2

Dyes with complex chemical shows poor biodegradability structure.Most of decolorizing microorganisms exists limited degradation function,low degradation efficiency and easy formation of secondary pollution.That is,traditional biological wastewater treatments face severe challenges.Therefore,in this work anthraquinone dye Disperse Red 3B were decolorized by consortium of the Chlorella sorokiniana XJK and Aspergillus sp.XJ-2.Results were as follows:?1?Optimization at the treatment conditions of Disperse Red 3B simulated wastewater by consortium:The inoculation ratio of fungi and microalgae was set as 1:2,fungi and microalgae were inoculated into simulated wastewater at the same time,pH was 6,the temperature was 25?,and the rotational speed was 160 r min^-1.In terms of dye decolorization,the decolorization rate of the consortium was nearly double that of the single system,which could reach 98.09%.In terms of COD,total phosphorus and ammonia nitrogen removal,the consortium was also higher than the single system,and the removal rate could reach 93.90%,83.90%and 87.60%,respectively.The consortium was also superior to the single system in terms of dye concentration tolerance and salt tolerance.When the dye concentration were up to 500 mg L^-1,there was still the decolorization rate of 74.34%.While the NaCl concentration was 20 g L^-1,the decolorization rate could still reach 62.34%.?2?Degradation was determined as the dominant decolorization mode in the decolorization process of the dispersed red 3B by the consortium,and the proportion of degradation was taken at74.01%.The results of enzyme activity assay showed that Lignin peroxide was the dominant enzyme.In the fourth day of decolorization,enzyme activity could reach 86.7 U L^-1 and 122.5 U L^-1,respectively.The infrared and temperament analysis results of the Dispersed Red 3B degradation products showed that the dye was degraded into small molecular substances,which could be mineralized,and the dye degradation pathway was simulated according to the experimental results.?3?Observing the morphological and microscopic consortium during the decolorization of Disperse Red 3B,the microalgae were entangled by hyphae,forming a compact spherical structure.The result of biomass measurement showed that the consortium had higher decolorization rate and biomass compared to the single system.In the consortium,microalgae play an important role in the removal of Disperse Red 3B.Through metabolism analysis,there were436 differential metabolites in the microalgae of the consortium compared to the cultured microalgae alone,of which 129 metabolites were significantly up-regulated,65 metabolites were significantly down-regulated,and 242 metabolites were not changed.It indicated that there was a synergistic relationship between fungi and microalgae in the consortium,and the fungi promoted microalgae degradation of dyes.The above research showed that the consortium existed higher treatment effect and adaptability in the treatment of printing and dyeing wastewater than the single system.The consortium of fungus and microalgae existed a good prospect of wastewater treatment.